Expression-controlling device.



H. J. LA 1015;

EXPRESSION CONTROLLING DEVlC-E.

APPLICATION FILED OCT-1.191].

1,296,819. Pdtented 1\[ar. 11,1919.

TRACKER BA R G-QVEPNOR TO EXPRESS ION DEVICE To TRACKER CHAM BER WIND CHEST GOVERNOR j WM, M% 2M% T 0 all whom it may concern:

UNITED STATES PATENT OFFICE.

HERBERT J. LA Joiner ORANGE, NEW JERsEY, n-ssreivon T0 AUTOPIANO coMPAn A CORPORATION on NEW YORK.

" EXPRESSION-CONTROLLING DEVICE.

Application filed October 1 1917".: Serial no. 194.1321.

- Be it known that I, HERBERT J. Li Jom,'a citizen of the United States, residing at Orange,in the county of Essex and State of New York, have invented a new and useful Expression-Controlling Device, of which the following is a specification. i

The object of this invention is to improve the accent controlling devices used in pneumatically operated musical instruments, and particularly to improve the well-known Welte Mignon action such as is'shown particularly in patent to E. Welte and K. Bockisch, No. 1,008,291, patented November 7, 1911.

This expression device consists of a num ber of expression controlling devices which are put into and out of operation by valves which are operated from apertures in the tracker bar, which are covered and uncovered by perforations in the note sheet, the valves connecting a chamber connected to the pumping apparatus with or disconnecting the same from said expression controlling devices.

In operation the pump under varying conditions will induce sometimes heavy and sometimes low ressures, and this has been found to inter ere with the operation of such valves.

To overcome this objection, I have arranged an automatic governor between said pump and said chamber so that the tension in said chamber will be substantially constant, whereby the valves will nicely work under all conditions.

In the drawing formingpart of this application for patent the improvement is represented diagrammatically in Figure 1, and Fig. 2 represents'a cross sectional elevation taken on the line 2-2 of Fig. 1.

Referring to the drawing and in detail, 10 represents an accent opening in the tracker bar which is connected by a tube to operate a diaphragm which controls a double valve 11 which is arranged to connect or disconnect the chamber with a tube 12 extending to control an expression device.

' The chamber is arranged on the top of the wind chest which is connected to the suction pump in any ordinary way, and the wind chest previously was connected directly to the chamber.

By this old arrangement the fluctuatlons of pressure caused by the suction pump Specification of Letters Patent.

Patented Mar. 11, 1919.

working under various conditions was apt to disturb the operation of the valves. This particularly was the case because in said device the valves were released by another controlling opening 18 in the tracker bar.

To overcome this objection, instead of con meeting the wind chest directly to the cham her I connect the wind chest through an opening B with a pneumatic which operates a valve A to control the opening B which has a spring C normally tending to expand the pneumatic, the pneumatic being connected to said chamber by a passa e -way 14. By this arrangement substantial y a constant tension is maintained in the chamber, whereby the fluctuations of tension from the pump working under various conditions will not eflect the action of the expression controlling valves.

In operation, when an opening 10 is uncovered in the tracker air will flow under the diaphragm through a double valve 11'.

at its top which is connected by a bleed ing passage down to the chamber in which the valve 11 works so that when said valve is lifted to uppermost position it will maintain its position until an'opening 13 is uncovered in the tracker bar, permitting atmospheric air to flow above the uppermost diaphragm, and allowing the valve to return to its seat.

It will be seen that in the operation of this valve a rather delicate balance is necessary. This balance was apt to be disturbed by fluctuations in the operation of the pump. By means of the pneumatic governor A, B, 0, previously described, this improper action is avoided and the valves open and stay open and close in exact accordance with the openings in the note sheet.

Details and arrangements herein shown and described may be greatly varied by a skilled mechanic without departing from the scope of my invention as expressed in the claims. v

Having thus fully described my invention, what I claim and desire to secure by Letters Patent is 1. In a pneumatically operated musical instrument, means forthrowing expression controlling devices into and out of operation comprising a chamber, a connection from said chamber to an exhaust pump, a governor arranged between said chamber and said connection for maintaining a constant tension in said chamber, connections from said chamber to the expression controlling devices, valves in said connections, means for operating said valves, a tracker having ace cent controlling openings, and connections therefrom to the means for operating said valves. I

2. In a pneumatically operated musical instrument, means for throwing expression controlling devices into and out of operation comprising a chamber, a connection from Copies'of this patent may be obtained for from said chamber to the expression con-i trolling devices, valves in said connections,

means for operating said'valves, a tracker having accent controlling openings, and'conhections therefrom to the means for operating said valves. I V

In testimony whereof I have hereunto affixed my signature, 1

' HERBERT J. LA JOIE.

five cents each,'by addressing the Commissioner of Patents, Washington, D. 0. 

